JPH0788696B2 - Prestressing device for large span frames - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention constructs a mountain-shaped large-span frame structure with a rod, a ball joint, and a bolt-shaped connector, and pre-installs the large-span frame structure in the span direction. The present invention relates to a prestressing device for a large span structure for introducing stress.

[Conventional technology]

In recent years, a stringed beam construction method has been attracting attention in which a tension member is passed through a parallel string truss, a mountain truss, or an arch truss suitable for a large span frame structure along the span direction and the tension member is pulled to introduce prestress to the entire truss. ing.

According to this type of construction method, since the tension member bears a part of the load, the member stress of the chord member can be remarkably reduced, whereby the member cross section and beam formation of the chord member can be reduced, and a large span can be achieved. This has the advantage that the bending of the beam center that cannot be avoided in the frame can be easily corrected.

By the way, the conventional stringed beam method generally uses shaped steel such as angle and CT, and the method of using a steel pipe or a ball joint as in the present invention causes bending force in these steel pipes and spheres, so that prestressing is performed. Was never used to introduce.

[Problems to be Solved by the Invention]

However, recently, large-span buildings with innovative shapes are being actively built as seen at expositions and the like.

For this reason, the truss beams are not only simply mountain-shaped or arch-shaped, but truss beams having various shapes are being used.

For example, when constructing a mountain-shaped large-span frame structure with rods, ball joints, and bolt-shaped connectors like the truss beam of the present application, such truss beams are prestressed in the span direction by the conventional stringed beam construction method. If you try to introduce it, a special metal object will be welded and fixed to the ball joint, and a tension member will be attached to this, so a bending force will be generated in the connector or rod at the base of the ball joint and the rod, and a string beam can be constructed. could not.

The present invention has been made in view of such circumstances,
An object of the present invention is to provide a prestress introduction device for a large span frame structure that can introduce prestress when a mountain-shaped large span frame structure is constructed with a rod, a ball joint and a bolt-shaped connector. Is.

[Means for solving the problem]

A prestressing device for a large span structure according to the present invention constructs a mountain-shaped large span structure with a rod, a ball joint and a bolt-shaped connector, and introduces prestress in the span direction of the large span structure. Concerning the pre-stress introducing device, the base metal fitting is fixed to the upper part of the lower structure that supports both ends of the large span structure, and the support body of the large span structure is movably supported on the base metal fitting. Bundles are erected at least in the ridge of the large span frame structure, the bundles are arranged at regular intervals in the direction of the girder, and the bundles are a plurality of members below the ridge. To form a space truss in the shape of an inverted quadrangular pyramid, and through which the through hole opened in the ball joint at the lower end of the space truss and the through holes of both end bearings are inserted to place the tension members, the tension members at both ends Of support Under the tension state from the side, it is constituted by fixing with fixing bracket the scaffold and the ball joint end.

〔Example〕

 Hereinafter, the present invention will be described based on an illustrated embodiment.

The large-span frame structure 1 is configured by arranging many rods made of steel pipe or the like three-dimensionally and systematically, and the entire frame constitutes a space truss structure.

Further, the large span frame structure 1 is formed in an equilateral mountain shape with the central part as a ridge when viewed from the side.

Among the many rods constituting the large span frame structure 1, the upper chord member 2 and the lower chord member 3 of the frame structure are continuously arranged in a substantially linear shape in the span direction when seen in a plan view.

In addition, a bundle 4 is erected on the ridge of the large span frame structure 1,
A bundle 5 is erected on the lower side of a substantially intermediate portion between the ridge and the support portions at both ends.

The bundles 4 and 5 are erected at the contact points between the lower chord member 3 and the diagonal members 6, and the lower end portions of the bundles 4 are connected to each other by four pieces by the ball joints 7. On the lower side, three-dimensional trusses a in the shape of an inverted quadrangular pyramid composed of four bundles 4 are formed at regular intervals in the girder direction of the large span frame structure 1.

Further, the lower end portion of each space truss a is continuously joined by installing a connecting member 8 between the ball joints 7, 7 of each space truss a along the girder direction.

At the left and right bearings of the large span frame structure 1, bearings 9 are installed at regular intervals in the direction of the girder.

The large span frame structure 1 configured in this way is bridged and fixed on the lower structure 10 such as a pillar or a beam.

A base metal fitting 11 is installed on the upper end portion of the lower structure 10, and the bearings 9 of the large span frame structure 1 are respectively installed and fixed on the base metal fitting 11.

A slide member 12 made of Teflon or the like is interposed between the support 9 and the base metal fitting 11 so that the support 9 before being fixed can be easily moved laterally.

The base metal fitting 11 has a plurality of legs under the base plate 13.
It is configured by projecting 14 pieces.

The base plate 13 is formed in a rectangular plate shape having a predetermined size, and a plurality of bonding holes 15 are formed in the central portion and the peripheral portion thereof. The joint hole 15 is formed in a long and slender elongated hole shape in the span direction of the large span frame structure 1.

The leg 14 is formed in a substantially groove-shaped cross section that opens directly above, and is fixed to the lower side of the base plate 13 by welding integrally in parallel therewith.

The base metal fitting 11 configured in this manner is installed in a state in which only the legs 14 and 14 are embedded in concrete on the lower structure 10, and the base plate 13 is substantially flush with the upper end of the lower structure. . Further, the bottoms of the legs 14 are integrally fixed to a plurality of anchor bolts 16 previously embedded in the concrete of the lower structure 10 by a plurality of fixing nuts 17.

The support 9 comprises a horizontal plate 18 and a plurality of vertical plates.
19 is welded and fixed, and the ball joint 7 is welded and fixed on the vertical plate 19.

A plurality of joint holes 21 correspond to the joint holes 15 of the base plate 13 and are formed in elongated holes in the span direction of the large span frame structure 1 at approximately the central portion and the peripheral portion of the horizontal plate 18. . Further, joining bolts 22 are respectively fastened to the corresponding joining holes 15 and 21, and the support 9 is fixed on the base metal fitting 11 by the plurality of joining bolts 22.

With this configuration, the left and right bearings 9 are attached to the base metal fitting 11
When the large span frame structure 1 is fixed to the lower structure 10, the position of the large span frame structure 1 can be adjusted by appropriately moving the large span frame structure 1 in the span direction.

In this case, since both the joining holes 15 and 21 are long holes, the large span frame structure 1 can be largely moved for the diameters of the joining holes 15 and 21.

Between the left and right bearings 9 of the large span frame structure 1, the bundle 5 and the ball joint 7 at the lower end of the space truss a, a tension member made of PC steel wire or the like is provided.
23 are laid continuously along the span direction.

The tension member 23 has its middle portion inserted through the bundle member 5 and the through hole 24 of the ball joint 7, and after being tense, is fixed to the end portion of the ball joint 7 by the fixing metal fitting 20.

Before the both ends of the tension member 23 are fixed, the tension member 23 is pulled from both ends by a hydraulic jack or the like, so that a predetermined amount of prestress is introduced into the large span frame structure 1 in the span direction.

The tension members 23 are arranged at regular intervals in the girder direction of the large span frame structure 1.

Next, a method of introducing prestress to the large span frame structure 1 in such a configuration will be described.

Before fixing the left and right bearings 9 of the large span frame structure 1 to the base metal fittings 11, the tension members 23 are pulled from both ends by hydraulic jacks or the like, and the large span frame structure 1 is prestressed to a predetermined size in the span direction. To introduce. Next, both ends of the tension member 23 are fixed to the support 9 by the fixing metal fittings 20.

Further, the tension member 23 is also fixed to the bundle member 5 at the middle portion and the ball joint 7 at the lower end of the space truss a by the fixing metal fitting 20.

Next, the left and right bearings 9 are positioned on the base metal fitting 11 and then integrally fixed.

In addition, after the prestress is introduced into the large span frame structure 1, the left and right bearings 9 are fixed because the ridge part is slightly elevated when the prestress is introduced, and as a result, the left and right bearings 9 are fixed.
Is to move inward.

〔The invention's effect〕

Since the present invention is configured as described above, it has the following effects.

A plurality of bundles are erected on the ridge, and three-dimensional trusses in the shape of an inverted quadrangular pyramid are formed on the lower side of the ridge by the plurality of bundles at regular intervals in the direction of the girder. Through the through holes formed in the ball joints at the bottom of the truss and the through holes formed in the ball joints of the supports at both ends of the large span structure, the tension members are laid along the span direction of the large span structure. Therefore, even if the prestress is introduced in the span direction, no bending force is generated in the connector or the rod at the base of the ball joint and the rod, and the deformation of the member can be prevented.

In addition, since the bearings at the left and right ends of the large span frame structure are movably fixed on the base metal fittings of the lower structure in the span direction, the movement of the bearings due to the introduction of prestress and the bearings for construction By absorbing the movement and the like, it can be securely fixed at a predetermined position, and the construction accuracy can be improved.

Further, a base metal fitting is provided on the lower structure supporting the large span frame structure, and a support body is provided at both end bearings of the large span frame structure, and a slender joint hole is provided in the span direction in the base metal fitting and the support body. In addition, since the support body is fixed on the base metal fitting by fastening the connection bolt to the connection hole, the structure is extremely simple, and the position adjustment of the support portion can be performed very easily.

Furthermore, both ends of the tension member are inserted into the through holes of the ball joints of the left and right bearings and fixed by the fixing metal fittings.
Since the middle part of the tension member is inserted into the through hole formed in the ball joint at the lower end of the space truss and is fixed by the fixing metal fitting, the tension member can be supported and fixed securely, and the tension member can be tightened. No special parts are needed to support and fix both ends and middle part of the material.

[Brief description of drawings]

1 to 5 show an embodiment of a prestressing apparatus for a large span frame structure according to the present invention. FIG. 1 is a schematic perspective view of the large span frame structure, and FIG. FIG. 3 is an enlarged detailed view of B portion in the drawing, FIG. 3 is an enlarged detailed view of C portion in FIG. 1, and FIGS. 4 and 5 are longitudinal sectional views showing details of left and right end bearing portions of the large span frame structure. 6 is the plan view,
FIG. 7 shows the fixing portion of the intermediate portion of the tendon A in FIG.
FIG. 1 ... Large span frame structure, 2 ... upper chord material, 3 ... lower chord material,
4,5 ... Bundle, 6 ... Slanting, 7 ... Ball joint, 8 ... Connecting material, 9 ... Supporting body, 10 ... Lower structure, 11 ... Base metal fitting, 12 ... Sliding member , 13 …… Base plate, 14 ……
Legs, 15 ... Joint holes, 16 ... Anchor bolts, 17 ... Fixing nuts, 18 ... Horizontal plate, 19 ... Vertical plate, 20
...... Fixing metal fittings, 21 ...... Joint holes, 22 …… Joint bolts, 23…
… Tension material, 24… Through hole.

Claims (1)

[Claims] 1. A prestressing device for constructing a mountain-shaped large-span frame structure using rods, ball joints, and bolt-shaped connectors, and for introducing prestress in the span direction of the large-span frame structure. On the upper part of the lower structure that supports both ends of the large span frame structure,
The base metal fitting is fixed, the support body of the large span structure is movably supported on the base metal, and at least a bundle material is erected on the ridge of the large span structure body. The bundles are arranged at regular intervals in the direction, and the bundle material constitutes a space truss in the shape of an inverted quadrangular pyramid with a plurality of members on the lower side of the ridge, and is opened to the ball joint at the lower end of the space truss. A tension member is arranged by inserting the through hole and the through hole of the both-end bearings, and the tension member is fixed from the outside of the both-end bearings in a tensioned state, and the bearing and the end portion of the ball joint are fixed with fixing fittings. Prestressing device for large span frames.